There was no immediate confirmation of the final resting place of any remaining debris.

"Most of the parts burnt up and disappeared," foreign ministry spokesman Geng Shuang told reporters, adding that China kept the United Nations space agency informed about the situation.

"According to my knowledge, we have not found any harm to the Earth's surface."

Tiangong-1 -- or "Heavenly Palace" -- was placed in orbit in September 2011, acting as a testing ground for China's efforts to build its own space station by 2022, but ceased functioning in 2016.

Space officials had promised the atmospheric disintegration of the 10.4-meter-long (34 foot) craft would offer a "splendid" show akin to a meteor shower.

But the remote location likely deprived stargazers of the spectacle.

Jonathan McDowell, an astronomer at the Harvard-Smithsonian Center for Astrophysics, said the module zoomed over Pyongyang and the Japanese city of Kyoto during daylight hours, reducing the odds of glimpsing it before it hit the Pacific.

"It would have been fun for people to see it but there will be other re-entries," McDowell told AFP. "The good thing is that it doesn't cause any damage when it comes down and that's what we like."

Space officials had warned that knowing the exact location of the re-entry would not be possible until shortly before it happened.

The difficulties seemed to wrong-foot Chinese space scientists -- just moments before announcing that the craft would come down over the Pacific, they had said it would make its re-entry over Sao Paulo and head towards the Atlantic Ocean.

The U.S. military's network of radars and sensors also confirmed that the Tiangong-1 had re-entered over the Pacific, but a minute later than the Chinese estimate, according to a statement by the Joint Force Space Component Command.

- Wrong guess -

McDowell said the China space agency's initial estimate for re-entry was off because it "guessed wrong" about the time the space lab would leave its orbital path.

"That's all that happened," he said, as models used by experts to estimate a re-entry point pick the middle time in a return window.

The European Space Agency had described the probability of someone being hit by debris from Tiangong-1 as "10 million times smaller than the yearly chance of being hit by lightning."

The module -- which was used to practise complicated manual and automatic docking techniques -- was originally intended to be used for just two years, but ended up serving considerably longer.

It hosted Chinese astronauts on several occasions as they performed experiments and even taught a class that was broadcast into schools across the country.

Huang Weifen, deputy chief designer of the Astronaut Center of China, said it played an important role in China's space history and provided "precious experience" for building a space station, according to the official Xinhua news agency.

In an article on a science ministry website, she said the lab achieved many "firsts" for Beijing's space program: the first manual docking of a spacecraft, the first flight by a female astronaut and the first lesson from orbit.

- Out of control? -

Tiangong-1 had been slated for a controlled re-entry but ceased functioning in March 2016. Space enthusiasts have been bracing for its return ever since.

The European Space Agency (ESA) has said ground controllers were no longer able to command Tiangong-1 to fire its on-board engines, which could have been used to determine where it re-entered Earth's atmosphere.

In contrast, Russia brought down its massive Mir space station through a controlled re-entry over the Pacific Ocean in 2001.

A Chinese spaceflight engineer denied earlier this year that the lab was out of control.

Chinese media have downplayed comments by the ESA and others that engineers had lost control of the lab, with reports saying the idea that it was "out of control" was an invention of foreign media.

The lab "re-entered the atmosphere because it ran out of fuel, not because it's out of control", according to an expert interviewed by the nationalist tabloid the Global Times.

Reports to the contrary, it said Monday, were because "foreign media envy China's space program."

China in 2003 became the third country able to launch humans into space, following the former Soviet Union and the United States.

China sent another space lab, Tiangong-2, into orbit in September 2016.